Helical wire end twister



lower position.

2,856,969 Ice Patented' Oct. 2l, 1958 HELICAL WIRE END TWISTER Charles C. Waful, South Gate, Calif., assignor to Spring Machinery Company, Los Angeles, Calif., a corporation of California Application November 1, 1954, Serial No. 466,054

3 Claims. (Cl. 140102) This invention relates to a mechanism to twist or form a loop in the ends of the helical wire members that connect the spring coils of a bed spring or the like. Ordinarily, two helical connectors are fed simultaneously to connect the upper and lower convolutions of adjacent rows of spring coils and four units or devices are ordinarily used for-twisting the two ends of each connector. Such twist or loop in the connector ends serves the two-fold purpose of preventing displacement of the connectors and obviating damage by said ends to fabric coverings.

An object of the present invention is to provide a twister device that is rapid in operation and, therefore, materially reduces the production time of a bed spring.

Another object of the invention is to provide a device of the character indicated that is easy to adjust after installation in a bed spring machine and which will remain in adjustment.

The invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in la working position and easily disconnected. therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. However, the drawing merely shows and the following description merely describes one embodiment of the present invention, which is given by way of illustration or example only.

In the drawing, like reference characters designate similar parts in the several views.

Fig. 1 is a top plan view of a twister unit according to the present invention.

Fig. 2 is a partial longitudinal sectional and partial elevational view of said unit, the same being shown in a raised position.

Fig. 4 is an elevational view as seen from the right of Fig. 2.

Fig. 5 is an enlarged detailed plan view showing the loop formed by the present unit.

The twister unit that is illustrated comprises, generally, a support frame 10, a twister member 11 guided in said frame and carrying loop-forming means 12 at the end thereof, means 13 to both partially rotate and project and retract the member 11, and pressure uid means 14 to operate the means 13.

The present device may be mounted as on a plate 15 to which the frame is aiixed as by means of screws 16.

The support frame 10 is shown as a relatively thick plate 17 of generally rectangular form and provided along one side with a recess dened between lateral projections 18 and 19. The projection 18 is provided with a guide bore 20 and with a counterbore 21 open at the end of the plate 17 that is engaged with plate 15. The projection 19 is provided with a guide bore Z2 aligned with bore 20 and with a recess Z3 in the wall surrounding the latter bore.

Said frame 10 further comprises a bracket 24 affixed to the side of plate .17.

The twister member 11 comprises a round shaft 25 that extends across the recess between projections 18 and 19 and is guided in the bores 20 and 22 of said projections. A head 26 on the end'of said shaft resides in counterbore 21 and limits the endwise movement of said shaft, said head engaging plate 15, when the shaft is retracted, and the base wall 27 of said counterbore, when the shaft is projected. A thrust washer 28 on said head is designed to allow rotation of head and shaft when said washer is engaged with wall 27. A laterally projecting pin 29 on said shaft extends in recess 23 when the shaft is retracted and is clear of said recess and projection 19 when the shaft is projected.

Intermediate the bearing for shaft 25, the latter is provided with a laterally directed pin 30v that is mounted in an anti-friction bearing 31 and, therefore, is rotational on its axis.

The loop-forming means 12 is of generally conventional formand in this instance, comprises a length of rod 32 secured in a seat provided in the end of shaft 25 and formed at its projectingend to have an eccentric wall 33 in which a transverse notch 34 isprovided. A pin 35 is arranged in spaced parallelism with wall 33, the same preferably being offset with respect to the axis of shaft 25 in the opposite direction to the eccentricityof wall 33.

The means 13 comprises a sleeve 36 around the shaft 25, a bracket 37 in which said sleeve islixedly connected as by means of a set screw 38, and opposite top members 39 and 40-the former to engage plate 15 to stop the bracket 37 in one direction and the latter to engage bracket 24 to stop the bracket 37 in the other direction.

As best seen in Fig. 3, the sleeve 36 is formed to have a helical cam groove 41 into which pin 30 projects; the angular extent of said groove being great enough to im.- part to the shaft 25 a magnitude of rotation that will produce the loop 42 in helix 43. Usually rotation of about 230 of the shaft 25 is required for the wall33 and pin 35 to produce a loop substantiallyas shown in Fig. 5.

The uid means 14 is shown as a cylinder 44 mountedA on bracket 24 and having therein a piston that is suggested by the piston rod 45. The latter is connected to bracket 37. The cylinder is of the double-acting type and, therefore, is provided with spaced connections 46 and 47- one for pressure fluid to project the 4shaft 25 and the other for iluid to retract said shaft.

In a spring machine, the path of feed -of a helical connector is above and clear of the means 12 when shaft 25 is retracted. When the present device is installed in up When iluid pressure is admitted into connection 46,A

the means 14 acts to project shaft 22. The iirst function of cam groove 41 is to create a lifting force on pin 30 and, thereby, to lift shaft 25 until stopped by head 26 engaging wall 27. lThis brings pin 29 out of recess 23. As can be seen, said recess is somewhat larger than the pin and limited rotation of shaft 25 may occur during this first movement of the cam sleeve. This movement brings the wall 33 and pin 35 into straddling position on either side of connector end 48, as in Fig. l, said end being in or in alignment with notch 34.

As projection of sleeve 36 continues, the cam groove 41 thereof will cause shaft to rotate so that wall 33 and pin 35 may produce a loop,42 in helical end 46. Stop 40 is provided to limit this movement of sleeve 36 and the thickness' thereof may be varied accordingly.

The return movement of shaft and sleeve 36 is effected by introducing pressure fluid in connection 47. To insure proper alignment of pin 29 .so the same may re-enter groove 23, a stop plate 49 is provided, the same acting to hold pin 29 aligned as the shaft 25 is retracted. Stop 39, engaging plate 15, limits the retractive movement of the shaft and sleeve.

While the foregoing has illustrated and described what is now contemplated to be the best mode of carrying out the invention, the construction is, of course, subject to modification without departing from the spirit and scope of the invention. It is, therefore, not desired to restrict the invention to the particular form of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. A twister device comprising a frame plate having an elongated side recess, lateral projections on said plate defining the ends of said recess and having aligned bores therein and having a groove in the upper surface of one of the projections extending continuously laterally from the bore, one of said projections having a counterbore aligned with the bore therein, the said projection embodying one end wall of said counterbore, a plate closing the latter and constituting the opposite end wall, said plate being enlarged to constitute a support base for the frame plate, a twister shaft spanning between the mentioned lateral projections and guided in the bores of said projections for both rotational and longitudinal movement, a head on the end of said shaft and disposed within the mentioned counterbore, said head being of a thickness substantially less than the length of said counterbore and limiting the endwise movement of the twister shaft to a movement to between operated and retracted positions of adjustment equal to the difference between said head thickness and distance between the mentioned end wall of the counterbore and the counterbore-closing plate, a pin rigid with the shaft and extending laterally from a portion thereof immediately outwardly of the upper Surface of the projection in which the groove is located and in position to be received Within said groove when, the shaft is in retracted position to prevent relative turning movement between the shaft and the plate, and which is free of the groove when the shaft is in operated position to engage relative turning movement of the shaft, a twister device carried by the end of the shaft opposite to the mentioned head and beyond the frame plate projection at said opposite end, a lateral pin provided in the shaft between the lateral projections, sleeve means provided with a helical cam groove around the twister shaft, said lateral pin being engaged in said helical groove, a

bracket connected to and extending laterally from the mentioned sleeve, a laterally directed bracket affixed to the frame plate in alignment with the bracket on the cam sleeve, and fluid pressure-operated means interconnecting said brackets to impart both endwise and rotational movement of the twister shaft.

2. A twister device comprising a frame plate having laterally extending longitudinally spaced-apart projections with aligned bores therethrough, a twister shaft dimensioned to have a length greater than the distance between the projections and received in said bores in a guiding relation for free rotational and axial movement, an abutment rigid with said shaft for movement therewith, longitudinally spaced apart stop means rigid with the frame plate and lying in the path of said abutment for limiting displacement of the abutment therebetween from normal retracted position to operated position, a twister device on the end portion of the shaft extending beyond the projections, a pin extending laterally from a portion of the twister shaft disposed between said projections, sleeve means having a bore dimensioned slidably to t about the twister shaft between said projections and dimensioned to have a length less than the distance between said projections and provided with a helical groove therein, said twister pin being operatively engaged with said helical groove, an actuating means operatively engaging said sleeve for axial displacement of the sleeve whereby the shaft is displaced from retracted to operated position when locked against relative movement and whereby the shaft is caused to turn relative the sleeve and frame plate when free for rotational movement and blocked against axial movement by said stops, and a twister-locking means effective while the shaft is in retracted position to prevent turning movement comprising a recess in the top surface of one of the projections and extending continuously outwardly from the bore, and a pin rigid with the shaft and extending laterally therefrom in position to be received in said recess when the shaft is in retracted position and to project beyond said recess to free the shaft for rotational movement when in operated position.

3. A twister device as claimed in claim 2 in which the projection from the frame plate in which the recess is located is provided with an upstanding abutment adjacent the recess to stop the pin in alignment with the recess for entrance into the recess during movement of the shaft from operated to retracted position;

References Cited in the le of this patent UNITED STATES PATENTS 1,050,348 Cronander Ian. 14, 1913 1,199,771 Ehrling Oct. 3, 1916 2,219,844 Lotter et al. Oct. 29, 1940 2,439,465 Gookin Apr. 13, 1948 2,663,038 Gail Dec. 22, 1953 2,679,816 Moore June 1, 1954 

